基于开路谐振环的电子自旋共振系统设计与表征

本文采用有限元电磁仿真设计了基于开路谐振环的微带线谐振器,并利用该谐振器搭建了电子自旋共振测试系统．该谐振器的3 dB带宽为58.7 MHz,且具有开放式的平面结构．对不同质量的二苯基三硝基苯肼（DPPH）样品测试结果显示本系统的室温自旋探测灵敏度可以达到9.66×10¹² spins/Gs Hz^1/2;对以微晶玻璃和硅片为基底的DPPH样品测试结果表明本系统能实现对大尺寸、高损耗样品的电子自旋共振信号的非破坏性测量．本系统为薄膜材料的缺陷研究以及相关的微波性能表征提供了便捷的手段．     

Dynamics of Spin Temperatures in EPR on Rapid Switching of the Frequency Detuning of a Saturating Field

In the framework of the spin temperature in EPR in the absence of interaction with the lattice, the time-dependent change in the spin temperatures of the Zeeman subsystem and dipole-dipole reservoir has been investigated theoretically in the high-temperature approximation. It is shown that amplification in the system can be obtained by switching the detuning of the saturating field frequency. The approach to the solution of the problem is based on the fact that during the process of switching and establishment of both temperatures the total energy of the Zeeman subsystem and of the dipole-dipole reservoir is preserved. It has been established that the values of absorption or amplification in the system depend on the frequency detunings of the saturating field. In the presence of a probe field, the possibility of determining the value of the local magnetic field related to the time of transverse relaxation of the system is demonstrated.__________Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 2, pp. 171–175, March–April, 2005.     

Inversion of the electron spin resonance signal from a P1 center in a synthetic diamond crystal

We have studied the electron spin resonance (ESR) of a 0.59 carat synthetic diamond single crystal at room temperature. The crystal was grown on a “split-sphere” apparatus in the Fe-Ni-C system by the temperature gradient method. After high-temperature/high-pressure treatment of the diamond, it was observed that as the microwave power supplied to the sample increased from 70 μW to 70 mW in an H₁₀₂ cavity, the ESR signal from the P1 center (a nitrogen atom substituting for carbon at a lattice point of the diamond crystal: C-form nitrogen) is inverted. In the original diamond (before high-temperature/high-pressure treatment), no inversion of the ESR signal was observed. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 9–12, January–February, 2006.